dies after reaching top speed

[dank]

I would not think that too much oil would do that.

The fact that when it stops it has to sit for a few min. before it will run again tells you it is running lean and causing the pistons to seize.

What are your carb settings?

If you are unsure if the fuel pump is working then premix the fuel at 50:1 and check it again. You don't have to block off the pump
when trying this. It will run fine but may foul a plug during long idle times. But if the oil pump has stoped sending enough fuel then the motor is probably damaged.

[ February 29, 2004, 10:39 PM: Message edited by: dank ]

[CBJETSKIER]

i was asking because when riding i wasnt paying attention to smoke out the rear but when restarted it was smoking alot as if there was to much oil i just want to be sure so i dont mess it up i dont know the carb settings yet. when i got the ski the guy said after getting it out of the shop he could never go faster than 30- 40 mph if that helps i will also change all fuel lines also

[Technical Support]

All but Sea-Doo is 10% of stock - about 108psi on a proper gauge, assuming 120 stock. SD is 5%.

[Skimmer]

2-stroke motors are much tougher than you give them credit there Member #2. I have seen PLENTY of skis, Kaw, Yam, S-doo, Polaris get FILLED with water in various conditons. Sometimes they have NOTHING wrong after turning them upside down, pulling plugs and fogging the hell outa them. Sure, I've seen broken reeds and some nasty salt water damage too. However, I think it is VERY harsh of you to tell this guy RIGHT OFF THE BAT that he NEEDS A NEW MOTOR. I realize you are in the biz of selling them but come on. What if this guy had pulled the motor(worse yet PAID someone to pull it) and sent it into you? With the comp reading he is getting it seems everything is fine motor wise. NOT ONE PERSON ASKED IF THE SKI MOTOR WOULD EVEN TURN OVER RIGHT AFTER IT STOPPED RUNNING. So, did/does it? + Is there a heat sensor warning light on this model?? Is it flashing? All motors, 2-stroke and 4, are amazing things. They can take a beating and keep going in MANY cases. Granted, a holed piston or melt downs happen on these babies, this is not the case (so far) with this guy.

Note to ski owner- PULL oil pump, get block off plate(cheap!) and go pre-mix. Its a sure SAFE BET to help you to the road of recovery.

[Technical Support]

It's smoking a lot because everytime you sieze it like that, you do more and more damage. The rings are no longer sealing properly and you are getting huge amounts of blow-by and unburnt oil/fuel. Stop screwing around and pull the engine out for tear down or you very well may end up with a nice set of broken cases when you finally put a rod through the bottom.

Skimmer - I'm not talking about flooding an engine, I'm talking about water in the fuel.

[ March 01, 2004, 12:10 AM: Message edited by: Technical Support ]

[Skimmer]

So then what is the MIN PSI "anyone" should have in their Polaris 750 cyl before they need a rebuild?

[CBJETSKIER]

i have 125 on all cyl. i used a matco compression gauge & a snap- on both read about the same i believe both gauges are proper so i know that there is not a hole in the piston if 105 is a good reading SKIMMER to answer your ? yes it will turn over but take a little while to run No warning lights are flashing if there is one so far i know theres no water in the tank, water/fuel seperator because i emptied them sun. going to block off oil pump sometime this week after i get service manual

[dank]

While you have the carbs off check to make sure they are still clean.

[Skimmer]

Does this ski have the extra fuel pump or still just one? If only one, is it a high out-put/up-dated model? If not you need one anyway. Most auto-part stores sell a fiberoptic light kit for pretty cheap, might want to pick one up. Pull the plugs and stick it in there and you should be able to see the walls of each cylnder to see if they a galled up or scratched so we can put the siezed piston bit to rest. this "should" save you the cost of new head-gaskets. while you at it, it never hurts to check the torque on the heads any way (regular maint) I think it is 24 or 28 lbs, find out for sure..
I have a friend with a Blaster that did something much like this and IT turned out to be a very, very small tear in fuel pump. Rebuilt it and it has been fine for three seasons now.

[CBJETSKIER]

it has an extra fuel pump but im removing both of them and installing 1 from a raider 1100 triple when blocking the oil pump off do i need to remove the bushing and drive gear the polaris manual does not say im also checking the carbs outand replacing all fuel lines and filter and going pre-mix

[Skimmer]

So whats the deal? Any thing new to report here or what???

[CBJETSKIER]

what do you have to remove in order to block offoil injection the polaris manual doesnt say anything about blocking oil inj. off please help i heard penz 2cycle synthetic is just as good as polaris oil is it or should i stay with polaris oil

[CBJETSKIER]

sorry had to go to Iowa will continue checking it out now that im back in Tx

[ccxp95]

This may or may not help! but I also have a sl750
I got it used last year and like you had the very same problem it would just die. After 15 min-or so it would finally crank and run for a short time ,then die again - the fix was simple there is a rubber hose that comes out of the cap on top of the fuel tank its purpose is to vent pressure off the tank .if it is clogged-or in my case someone had blocked it off by putting a screw in end of the hose,-as you ride, it causes your tank to collapse inward causing enough back pressure on the fuel lines to stop the flow of fuel to the fuel pump and carb causing it to die.you noticed after it sat for 15 min or more it would start ? thats because enough presure had leaked from your tank to allow it to start again for a short time,I would check this before tearing down your engine-hope this helps!

[Technical Support]

You need to remove your oil pump and injection lines. The pump hole gets blocked with a plate and the injection fittings get capped. We sell the kit for $15.